Amplifier for phonographs



B. BOLTON.l AMPLIFIER FORPHONOGRAPHS. AP

PLICATION FILED OCT-23,1919.

Qteuted Mar. 22, 1921,

Eemian-1in Ejcnlfm- Smm/nto@ 'tain new and useful UNITED* STA-Tas PAT-ENT OFFICE.

BENJAMIN BOLTQN, F SALT LAKE crrY, UTAH."

AMPLIFIER nos, rnonoenae'ns.

Application and october as, 191e.

To all whom may concern Be it known that l, BENJAMIN BOLTON, a

nify the musicor sound reproduced by a l metallic sound to the music which mechanism reproducer, and one which wil-l be free fromV any metallic sounds, resulting inthe reproducing of clear lifelike notes and sounds.

It is -a well known fact thatfin even the most expensive gramophones of approved type now in use, there is more or less 1s reproduced and transmitted through a' metal horn, the action of the metal in the horn often distorting' and ,destroying some of the most beautiful notes reproduced, and it `is an object of this invention to provide a horn or sounding board structure which is en-` tirely free from any metal in its construction, being constructed of plastic material, reinforced by fabric and wood` so as to pro vide a comparatively rigid unbreakable reproducing horn in which the ill effects of metal are entirely eliminated as well as one which will reproduce the finest notes or sounds in their true state. e e Other objects ofthe invention will appear in the following detailed description taken in connection with the accompanying drawing, forming a part of this specification and in which drawing:

Figure 1 is a side elevation, partly in section, of ahorn constructed in accordance with this, invention.'

Fig. 2 is a cross section taken on the line 2-2 of Fig. 1-. Fig.v 3 is a section on thepline 3-3 of Fig. l.

Referring more particularly to the drawings, wherein like characters indicate like and corresponding parts throughout. the several views, the improved horn or sound board `10 may be constructed in anydesired shape, without departing from the spirit of this invention, and it is composed of superposed'layers' of plastic material and fabric Speccation or" Letters Patent.

yhaving a. layerjll of 'the interior A face of which the fabric layer 12 is placed.

upon the inner layer 11, it

Patented Mer. 22, 1921. senat No. ,332,609. l

plastic material, at thereof, against the outer sur- Thislayer 12 maybe ofcanvas, burlap or any analogous fabric', and prior to placing is preferably impregnated with `-liquidy plastic material and adhesive, such as liquid plaster of Paris and `glue. VTo reinforce' and brace the horn structure 10, a plurality-'of bracing strips 13 of wood, preferably pine, are placed upon the outer surface of the-'fabric layer 12 at circumferentially spaced points, and they extend longitudinally of thehorn structure, serving to`reinforce the same and lprevent accidentalV breaking gof any part 'thereof Fabric strips .14 are placed over the outer surfaces of the strip 13 andthe coating of plastic material 14 is then placed over the outer surface of thel fabric layer 12, and

fabric strips 14', entirely inclosing these portions of the horn structure.

The L neck 15, of the horn .structure is made up of' an inner` layer 16 of. plastic ma terial, an intermediate layer 17 of fabric, an outer layer 18 of plastic materialv preferably impregnated with glue or analogous adhesiveJ and as shown in Fig. 340i' the drawings', it is necessary to make this portion ofthe horn in sections. andfat times it maybe necessary to make the entire horn in `sections depending upon the configuration thereof, and when the entire horn ism'adc in section, the adjacent or facing'A edges of` soI the horn are placed in engagement with each other, after the outer plastic layer 18 has been properly and set or hardened, after i.

which strips 19 the 'meeting edges of the'sections and a layer of coatingQO of the plastic material impregnated .with glue is then placedl over the strips 19 and the layer 18 of plastic -material, thoroughly welding the sections of the horn or sounding board in properly con- Y nected position.

In constructing the horn, or sounding board, the following method is carried out. A mold of the shape in which the horn or sounding board is t0, be made is provided, and this mold is first coated, with a coating or' liquid plastic material preferably plaster of Paris, whichis mixed with water oran other suitable liquid to substantially the consistency o f cream. However, prior to the coating of the mold, it is oiled or greased, so that 'the cast when set or hardof fabric are placed overened will easily come off or free from the mold. The semi-liquid plastic material is' placed over the mold, preferably with a brush, so as to evenlyl distribute this plastic material over the entire surface of the mold. After the mold is coated vwith' the plastic material of substantially the consistency of cream, a second quantity of plastic material is made, which comprises a suitable quantity of plaster of Paris, or analogous plastic material which is moistenedandr mixed to a semi-liquid state, by half a tea-cup full of glue' water, to each quart of pure water used in the mixing. The glue water is made from four ounces-of powdered glue to one quart of water, pending upon the quantity made. From the plaster of Paris or analogous plastic material, mixed with the adhesive, 'the 4semiliquid plastic material is provided,V with which a'second coat orlayerjs put upon the mold, over the first coat, after this first coat has started to harden or set. How- 'sufficiently ever,'.care should be taken to apply Vthis second layer or-coat of plastic material impregnated with adhesive, before the first coat becomes thoroughly hardened, other-l Wise, they willnot 'pi'c' perly co-mingle to form the innermost portion of the sounding board4 or horn, etc. This second coat or layer should be put upon the first layer by a brush of the type used in cleaning and ric, such as" burlap, canvas, or analogous materialwhich has previously been cut to the shape wanted is dipped in the-semiliquid mixture of .plastic material and adhesive and it is then placed over the mold about theVA coats of adhesive material and Iplastic material and smoothed out to lie flat thereover. Strips of pine wood, are then placed at the desired position circumferentially of the horn structure, 'and extend longitudinally thereover. After the. strips of wood, preferably pine or analogous soft wood have been placed,vstrips offabric, such as vburla-p, canvas or the like, which have been impregnated with the mixture of plastic material and adhesive, are placed over the outer'surfaces of the longitudinally extending wood bracing strips and av layer of the admixed plastic material and adhesive is then put over these fabric strips and the portions of the first fabric strips which are still-exposed to the desired thickness so as to thoroughly weldthe fabric strips which cover thewood strips to the layer of fabric and, draw the various parts of the' horn or sounding board structure together, forming a unitary structure, which when vhardened or set is removed from .the mold.

I n makinga horn or soundingl board in sections, the/joints are wrapped `or covered with strips of canvas or analogous fabric'which or Ain such proportion, de-

to provide a relatively thin, even layer, thereof, after which the layer of fab-` but; l

has been previously impregnated with the admixed plastic material and adhesive, after which this fabric -is coated over with a coating or layer of the a'dmix'ed plastic material and-adhesive, thoroughly welding the various parts or'sections of the sounding board i or horn structure.

While in the'drawings, av horn, such asidesigned for use on an approved type of gramophone is shown, it is to be understood that sounding boards may be made for /lining music rooms in accordance vvitlrthe above method, the bodies of the various typs of instruments, such as 'the violins, may

lbe made accordingl to this method, so as to provide sounding 'boards which are free' from any 'metallic sound, and which will reproduce or transmit .sounds or notes in their true state; i l y The plastic' material is what is known` as a dead material, however, when' it is employed'infconnection with the fabric and adhesive, a very liv'sound deflecting or carryw I claim: l. Asl 'a sound horn for ,gramophones, comprising a layer of plastic material, a layer of admixe'd plastic material and adhesive, and a layer of fabric: l

2. As a new article of Amanufacture, a

new article of manu-facture, 'a

sound horn for gramophones composed of plastic material, fabricy tand reinforcing strips of wood.. I

iio

3. As a new article of manufacture', sound horn for gramophones composed of'a layer c of plastic material, a layer of admixed plastic material and adhesive, a layer of fabric, and a layer of admixed plastic material and adhesive uponsaid fabric layer.

4. As a new article of manufacture, a sound horn for gramophones composed of a` layer o f plastic material, a layerof admixed plastic material and adhesive, a layer of fabric,A

` longitudinally extending bracing strips of wood upon said fabric layer, and a coatingl of admixed adhesive and `,plastic material upon said bracing strips and fabric layer.

5. As a new article of manufacture, a,

sound hornV for gramophones composed of la layer of plaster of Paris, a vsecond layer of adm ixed plaster of Paris and glue, av layer of fabric upon said admixed layer,

and a slayer and glue upon said fabric layer.

@Ms a new article of manufacture, a soundhorn for .gramophones composed of plaster of Paris, admiXed plaster of Paris and glue, and fabric.

7. As a new article of manufacture, a sound horn for gramophones composed of a plurality of sections, each of said sections composed of superposed layers of plastic material, adiniXed plastic material and adhesive, and fabric, and strips of fabric placed over the joints of the sections, said connecting fabric strips covered with admixed plastic material and adhesive.

8. That method of making sounding horns for gramophones Which consists in first coating a mold With liquid plastic material, coating the resulting article with ad-.

mixed plastic material and liquid adhesive, placing a layer of reinforcing fabricover the coating of admiXed plastic material and adhesive, and placing a layer of finishing material over the saidfabric layer.

9. That method of making sounding horns for gramophones which consists in rst coating a mold with liquid plastic material, coating the resulting article with admiXed plastic material and liquid adhesive, and placing a layer of over the coating of admiXed plastic material and adhesive, and placing a layer `of admiXed plastic material and adhesive upon said fabric layer.

oflradmixed plaster of Paris reinforcing fabric 10.Tliat method of making sounding horns for gramopliones which consists in coating a mold With liquefied plastic material,

coating the resulting article With admiXed horns for gramophones which consists in coating amold With liquefied plastic material,

coating the resulting article with admiXed plastic material and liquid adhesive, placing a layer of reinforcing fabric over the coating of admiXed plastic material and adhesive, placing reinforcing strips of Wood upon said fabric layer, placing strips of fabric over said reinforcing strips, and coating said strips of fabric and fabric layer with an admixtur'e of plastic material and adhesive.

l2. That method of making sounding horns for gramophones which consists in first coating the mold with liquefied plastic in aterial, coating the resulting article with an admiXed plastic material and liquid adhesive, placing a reinforcing element on said admixed plastic material and liquid adhesive and applyinga finishing material to the said reinforcing element.

BENJAMIN BLTUN. 

